Subslot PUCCH Resource Selection for URLLC Feedback Latency

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Solution Overview

Problem

The existing 5G mobile communication systems face challenges in reducing feedback latency and improving data transmission reliability for ultra-reliable low-latency communication (URLLC) services due to inconsistent availability of Physical Uplink Control Channel (PUCCH) resources across subslots, especially in Time Division Duplex (TDD) scenarios, leading to increased latency and reduced reliability.

Innovation Solution

Configuring a first PUCCH resource set at a subslot-level and allowing the terminal device to select a second PUCCH resource set for each subslot based on availability, ensuring each subslot has an available resource, thereby reducing feedback latency and enhancing data transmission reliability while minimizing redundant signaling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a network device uniformly configures PUCCH resource sets for all subslots, then the configuration is simple and consistent, but some subslots have no actually available PUCCH resources due to TDD and slot boundary limitations, increasing feedback latency and reducing reliability

Engineering Contradiction:
ImprovePUCCH resource configuration complexityVSAvoidfeedback reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent segments the PUCCH resource configuration by dividing subslots into different types (first subslot type and second subslot type) based on their availability characteristics. Different PUCCH resource sets are configured for different subslot types, allowing the system to address the unavailability issue in specific subslots without reconfiguring all subslots, thus resolving the contradiction between configuration simplicity and feedback reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by configuring PUCCH resources specifically for subslots that actually have available resources (first subslot type), rather than uniformly configuring all subslots. This localized configuration ensures that PUCCH resources are available where needed while maintaining simple configuration for subslots where resources are naturally available, thereby improving feedback reliability without significantly increasing overall configuration complexity.

Inventive Principle:
Principle #3Local quality

2Loss of time

If PUCCH resources are configured for every subslot, then feedback latency is reduced, but redundant signaling overhead increases when some subslots have no available resources

Engineering Contradiction:
Improvefeedback latencyVSAvoidsignaling overhead
Core Design Contradiction:
Loss of timeVSLoss of information

Solution Approach 1:

The patent extracts and identifies the subset of subslots that actually have available PUCCH resources (first subslot type) and configures PUCCH resource sets only for these subslots. By taking out the unnecessary configurations for subslots with no available resources (second subslot type), the patent reduces signaling overhead while maintaining low feedback latency for the subslots that actually need PUCCH resources.

Inventive Principle:
Principle #2Taking out (Extraction)

3Loss of time

If subslot-based HARQ-ACK feedback is implemented, then feedback latency is reduced, but PUCCH resource availability becomes inconsistent across subslots due to TDD and slot boundary limitations

Engineering Contradiction:
Improvefeedback latencyVSAvoidPUCCH resource availability consistency
Core Design Contradiction:
Loss of timeVSStability of the object's composition

Solution Approach 1:

The patent introduces dynamics by classifying subslots into different types based on their availability characteristics and configuring PUCCH resources dynamically according to subslot type. This allows the system to adapt to the varying availability conditions in different subslots caused by TDD and slot boundary limitations, ensuring consistent PUCCH resource availability where needed while maintaining the benefits of subslot-based feedback for reducing latency.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3993539B1Communication method and communication device
Publication Date: 2025.06.25 HUAWEI TECH CO LTD
  • EP3993539B1 patent drawingFigure 1
  • EP3993539B1 patent drawingFigure 2
  • EP3993539B1 patent drawingFigure 3~4

AI summary

This application provides a communication method and a communication apparatus, to reduce a feedback latency of a URLLC service and improve data transmission reliability. The method includes: receiving configuration information, where the configuration information is used to configure a first physical uplink control channel PUCCH resource set, and each PUCCH resource in the first PUCCH resource set is configured at a subslot-level subslot-level; determining a second PUCCH resource set of a subslot from the first PUCCH resource set, where the second PUCCH resource set includes an available PUCCH resource of the first PUCCH resource set in the subslot; and sending feedback information for downlink data on the available PUCCH resource in the second PUCCH resource set.